On TOA estimation of vibration signals for localizing impacts on solid surfaces

We propose a TDOA-based algorithm for source localization on rigid surfaces. This allows the conversion of readily available large surfaces into touch interfaces using surface-mounted vibration sensors. To achieve this, we characterize the arrival of each sensor-received signal by the arrival times of its frequency components. To estimate the arrival time of each frequency component, we first model each component as a harmonic random process. A kurtosis sequence, which exhibits a sharp rising edge when the signal begins to deviate from the background noise, can then be obtained for each component. By accurately estimating the starting point of the rising edge, our algorithm can avoid the uncertainty due to gradual noise-to-signal transition. Experiment results show that the proposed algorithm achieves better localization performance than existing techniques on large surfaces.